番茄 SlWRKY46 调控低温胁迫响应的功能研究

In order to explore the function of SlWRKY46 in response to low temperature stress,the CDS sequence of SlWRKY46 cloned from tomato‘Micro-Tom’leaves was analyzed. The result showed that SlWRKY46 belonged to Ⅱa group of WRKY family and encoded 253 amino acids. SlWRKY46 was localized in the nucleus by subcellular localization analysis. SlWRKY46 had no transcriptional activation activity in yeast. SlWRKY46 could form homologous dimers by yeast two-hybrid yeast (Y2H). The results of real-time fluorescence quantitative PCR(qRT-PCR)showed that the expressions of SlWRKY46 were significantly induced by low temperature and abscisic acid(ABA). The GUS staining of SlWRKY46 promoter transgenic tomato also cloud be induced by low temperature and ABA. The overexpressed SlWRKY46 tomato lines had higher cold tolerance compared with wild-type. The overexpressed SlWRKY46 tomato lines exhibited lower reactive oxygen species accumulation and malondialdehyde levels,and higher antioxidant enzyme activities and proline accumulation compared with wild-type under low temperature treatment. The expression levels of genes related to antioxidant enzyme and ABA showed significant differences between overexpressed SlWRKY46 tomato lines and wild-type under low temperature treatment. Taken together,these results indicated that SlWRKY46 positively regulated the cold tolerance of tomato by antioxidant enzyme and ABA pathways.